A Reuters investigation has concluded that an Iranian coalition was behind the September 14 attack on the oil facilities of oil giant Saudi Aramco, with Iran’s Supreme Leader Ayatollah Ali Khamenei giving the order to attack, according to Arab News, citing the Reuters report released on Monday.

The attack came after several secret meetings, starting in May, involving the top echelon of the Revolutionary Guard Corps, according to three officials familiar with the meetings, and a fourth official close to Iran’s decision-makers.

"It is time to take out our swords and teach them a lesson” a senior commander at one of these secret meetings. But ultimately it was decided that the attacks, says Reuters sources, were to stay within strict guidelines, stopping "short of direct confrontation that could trigger a devastating US response.”

They also needed to make sure the attacks did not hit any civilians or Americans, according to the sources.

Iran has again denied that it had any involvement in the attacks on September 14 that took offline roughly half of Saudi Arabia’s total oil production—at roughly 5 million barrels of crude oil per day.

The Houthi rebels in Yemen, who largely are aligned with Iran, claimed responsibility for the September attack, promising even more painful attacks should Saudi continue its campaign in Yemen.

The United States has worked to build up its military presence in the Persian Gulf, but still, Iran may "attack again” the chief of the US Central Command, General Kenneth McKenzie said in an interview with Foreign Policy over the weekend.

"I think the strike on Saudi Aramco in September is pretty indicative of a nation that is behaving irresponsibly,” McKenzie said, adding that in his judgement, it was "very possible they will attack again.”